Widow of Mineral Rights Owner

I received West Virginia mineral lease offer from a company called Antero that was addressed for my husband who passed away earlier this year. I have no idea what I need to do or if I should even do anything. The lease offer is in his name. I emailed the Landman listed and he responded with ‘there are 182 mineral owners for this 10 acre mineral tract’ and that he would send me an affidavit of heirship. What does that even mean? I was advised that it may help to get a mineral land lawyer to assist?? My finances are limited and this feels like that would be costly to only find out my next steps if any. Would you have any suggestions or even just thoughts on if this would be worth looking into since my husband is deceased.